#1 - good
#2 - (assuming you don't know algebra)
make a list that match the description:
1/7 , 2/9, 3/11, 4/13, 5/15=1/3 , yeahhh
#3 - good
#4 - why not do what you did in #3, they are the same question.
however , if you picked 20/30 , the HCF would be 10 not 5
so the trick is to first reduce 4/6 to 2/3
now 2/3 -----> 10/15
notice the HCF of 10/15 is 5
and since 4/6 = 2/3 , and 10/15 = 2/3
4/6 <-----> 10/15
#5 no
the smallest prime number is 2, 1 is not considered a prime number, so you want
2/3
#6, the prime numbers are
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, ....
can you find a pair which adds up to 24 ?, then form the fraction
I need some help on some of these, finding which fraction it would be with clues. I answered some, but some I need help on:
1. My numerator is 6 less than my denominator
I am equivalent to 3/4.
My answer to number 1: 6/12
2. My denominator is 5 more than twice my numerator
I am equivalent 1/3
My answer: Do not understand
3. The GCF of my numerator and denominator is 3.
I am equivalent to 2/5.
My answer: 6/15
4.The GCF of my numerator and denominator is 5.
I am equivalent to 4/6.
Answer: Don't understand.
5. My numerator and denominator are prime numbers.
My numerator is one less than my denominator
My answer: 1/2
6.My numerator and denominator are prime numbers.
The sum of my numerator and denominator is 24.
My answer: Don't understand
Please help me
2 answers
#1 Huh? 1:6/12 = 12/6 = 2
How does that relate to what they said?
You need to set the words to math:
(d-6)/d = 3/4
4(d-6) = 3d
4d-24 = 3d
d = 24
check:
18/24 = 2/3
yes.
As with most skills, with a little practice it gets easier.
#2
n/(2n+5) = 1/3
3n = 2n+5
...
#3
Since 2 and 5 have no factors in common, just make sure 3 is a factor in the equivalent fraction
2/5 = 6/15
GCF = 3, so that works
#4
4/6 .. 4 and 6 do not have 5 as a factor, so
4*5/6*5 = 20/30
However, GCF(20,20) = 10
So, reduce the fraction first to get rid of other factors
4/6 = 2/3
2*5/2*5 = 10/15
Now GCF(10,15) = 5 and 10/15 = 2/3
#5
With one exception, all primes are odd numbers, which differ by at least 2. The only even prime is 2, so the fraction is 2/3
#6
You need two odd numbers whose sum is 24, and they are both primes. So, what are the choices?
3+21, no
5+19, yes
7+17 yes
9+15 no
11+13 yes
That's all we need to check - stop halfway there, because then we start getting repeat values.
How does that relate to what they said?
You need to set the words to math:
(d-6)/d = 3/4
4(d-6) = 3d
4d-24 = 3d
d = 24
check:
18/24 = 2/3
yes.
As with most skills, with a little practice it gets easier.
#2
n/(2n+5) = 1/3
3n = 2n+5
...
#3
Since 2 and 5 have no factors in common, just make sure 3 is a factor in the equivalent fraction
2/5 = 6/15
GCF = 3, so that works
#4
4/6 .. 4 and 6 do not have 5 as a factor, so
4*5/6*5 = 20/30
However, GCF(20,20) = 10
So, reduce the fraction first to get rid of other factors
4/6 = 2/3
2*5/2*5 = 10/15
Now GCF(10,15) = 5 and 10/15 = 2/3
#5
With one exception, all primes are odd numbers, which differ by at least 2. The only even prime is 2, so the fraction is 2/3
#6
You need two odd numbers whose sum is 24, and they are both primes. So, what are the choices?
3+21, no
5+19, yes
7+17 yes
9+15 no
11+13 yes
That's all we need to check - stop halfway there, because then we start getting repeat values.